Question 1

Which of the following statements best describes the process of natural radioactivity?

Accepted Answer

It is the emission of small particles or energy from unstable nuclei to become more stable.

Question 2

Which type of radiation is identical to a helium nucleus?

Accepted Answer

Alpha particle

Question 3

What is the correct nuclear equation for the alpha decay of $$^{241}_{95}Am$$?

Accepted Answer

$$^{241}_{95}Am \$$rightarrow ^{237}$$_{93}Np $$+ ^{4}$$_{2}He$$

Question 4

A radioisotope emits a beta particle. What happens to its atomic number and mass number?

Accepted Answer

Atomic number increases by 1; mass number remains the same.

Question 5

Which type of radiation requires the most shielding to protect against its penetration?

Accepted Answer

Gamma rays

Question 6

A Geiger counter detects radiation by:

Accepted Answer

Detecting ions produced by radiation to create an electrical current.

Question 7

Which unit is used to measure the biological effect of radiation in humans?

Accepted Answer

Rem

Question 8

If a sample of $$^{90}Sr$$ has a half-life of 38.1 years, how much of a 36.0 mg sample remains after 152.4 years?

Accepted Answer

2.25 mg

Question 9

Which of the following radioisotopes is most likely to be used in nuclear medicine?

Accepted Answer

$$^{131}I ($$half-life 8 days)

Question 10

Which of the following describes nuclear fusion?

Accepted Answer

Small nuclei combine to form a larger nucleus.

Question 11

What is the correct nuclear equation for the beta decay of $$^{42}_{19}K$$?

Accepted Answer

$$^{42}_{19}K \$$rightarrow ^{42}$$_{20}Ca $$+ ^{0}$$_{-1}e$$

Question 12

A positron emission from a nucleus results in:

Accepted Answer

The atomic number decreases by 1.

Question 13

Which of the following is true about gamma radiation?

Accepted Answer

It is pure energy and does not change the mass or atomic number of the nucleus.

Question 14

A dosimeter is used to measure:

Accepted Answer

The amount of radiation exposure received by a person.

Question 15

Which equation correctly represents the production of a radioactive isotope by bombarding $$^{58}_{28}Ni$$ with a proton?

Accepted Answer

$$^{1}_{1}H $$+ ^{58}$$_{28}Ni \$$rightarrow ^{55}$$_{27}Co $$+ ^{4}$$_{2}He$$

Question 16

If the half-life of $$^{123}I is 13 $$hours, how much of a 64-mg sample remains after 26 hours?

Accepted Answer

16 mg

Question 17

Which of the following is a correct statement about the biological effects of radiation?

Accepted Answer

Gamma rays are damaging because they travel a long way through body tissue.

Question 18

What is the equivalent dose in rems for an absorbed dose of 5 rads of alpha particles?

Accepted Answer

$$100 	ext{ rem}$$

Question 19

Which of the following best describes a nuclear chain reaction?

Accepted Answer

Each fission event produces neutrons that cause additional fission events.

Question 20

Which of the following is a real-world application of radioisotopes in medicine?

Accepted Answer

Using $$^{131}I to $$diagnose and treat thyroid disorders.

Chapter 5: Nuclear Chemistry – Introduction and Natural Radioactivity

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